Do not use new struct type where unnecessary.

test/cctest/interpreter/bytecode_expectations/ArrayLiterals.golden

Index: test/cctest/interpreter/bytecode_expectations/ArrayLiterals.golden
diff --git a/test/cctest/interpreter/bytecode_expectations/ArrayLiterals.golden b/test/cctest/interpreter/bytecode_expectations/ArrayLiterals.golden
index 5bb33d4709b2b2770b1f537345cd21269758a274..affedc42369d16e27a7670d37e52444621c68494 100644
--- a/test/cctest/interpreter/bytecode_expectations/ArrayLiterals.golden
+++ b/test/cctest/interpreter/bytecode_expectations/ArrayLiterals.golden
@@ -18,7 +18,7 @@ bytecodes: [
   /*   51 S> */ B(Return),
 ]
 constant pool: [
-  CONSTANT_ELEMENTS_PAIR_TYPE,
+  TUPLE2_TYPE,
 ]
 handlers: [
 ]
@@ -49,7 +49,7 @@ bytecodes: [
   /*   66 S> */ B(Return),
 ]
 constant pool: [
-  CONSTANT_ELEMENTS_PAIR_TYPE,
+  TUPLE2_TYPE,
 ]
 handlers: [
 ]
@@ -67,7 +67,7 @@ bytecodes: [
   /*   62 S> */ B(Return),
 ]
 constant pool: [
-  CONSTANT_ELEMENTS_PAIR_TYPE,
+  TUPLE2_TYPE,
 ]
 handlers: [
 ]
@@ -110,9 +110,9 @@ bytecodes: [
   /*   77 S> */ B(Return),
 ]
 constant pool: [
-  CONSTANT_ELEMENTS_PAIR_TYPE,
-  CONSTANT_ELEMENTS_PAIR_TYPE,
-  CONSTANT_ELEMENTS_PAIR_TYPE,
+  TUPLE2_TYPE,
+  TUPLE2_TYPE,
+  TUPLE2_TYPE,
 ]
 handlers: [
 ]